The production of the factory has grown to in 1999.A. twice as it wasB. twice what it was

问题补充：

The production of the factory has grown to in 1999.

A. twice as it was

B. twice what it was

C. as twice as it was

D. twice that it was

答案：

A. twice as it was

(答案→)B. twice what it was

C. as twice as it was

D. twice that it was

解析：介词to后接一个有关倍数的宾语从句，其结构为：倍数+what it is，what 在从句中做表语，因为一般表示多少倍都是修饰主语，为主+be+表的结构，故选B。